Difference Between Online and Offline UPS

Characteristics	Online UPS	Offline UPS
Inverter	Inverter always remains ON all the time and provides output Power.	Inverter is switched on only is main supply is off.
Switching Time	Online UPS has switching time between 0-1 ms	Switching Time is generally <5 ms.
Area of Use	Generally used in large organizations and the areas where perfect UPS supply is needed.	Generally used for personal use at homes or small offices.
Inverter Design	Sine wave PWM Inverter is used.	Quasi Sine wave inverter is used.
Batteries  Location	External batteries are used with high capacity models.	Generally uses internal batteries.
Batteries Type	Tubular Lead acid batteries are used.	SMF (Sealed Maintenance Free) Batteries are used.
Backup Duration	Few Minutes to few Hours. E.g. 30 Minutes to 10 Hours.	10 to 20 Minutes Only.
MOSFET/IGBT Use	Uses MOSFET and IGBT	Only uses MOSFET
Price Range	Very High	Low
Size	Large and bulky	Small and portable
Input Supply Type	Three Phase	Single Phase